Antihalation film



July. 14, 1942 G. F. NADEAU ET AL 2,289,799

\ ANTIHALATION FILM l `Filed March-4, 1941 CE/.LL/LOSE vM/AED ESTER SUPPORT CELLULOSE ESTER SUBE/N6 LAYER.

ANT/HALAT/ON LAYER CO/YTQlN//YG CELLULOSE ACETATE PHTHALATE AND/4 OVE 0R COLLO/DAL CARBON.

cELLuLosEM/XED ESTE/QSUPPOR'I:

@f5/N susa/Ns A YER.

ANT/HALAT/o/v A YER conm/Nwe CELLULOSE ACETATEY'RHTHALATE ANO ,4 ove q@ conc/@AL cARo/v.

CELLULOSE MIXED ESTER SUPPORT M/XED CELLUL OSE ESTER AND RES/N SUB//YG LAYER.

ANT/HALAT/O/Y LAYER CONTA/NNY@ .CELLO/.OSE ACETATE PHTHALATE ANDA DYE 0R COLLO/DAL CARBON.

w 4 GALE/I'NADEAU ALFREDQIQSCK BY .QI

A 'ITORNE YS "insultan Ju1y"u14,;942

' UNITED STAT las PAT 131W; OFFICE.

ANTIHALATION FILM Gale Nadeau and Alfred D. Slack, Rochester, N. Y., assignors toEastman Kodak Company, Rochester, N. Y., a corporation or New Jersey Application Marchi, y1941, serial No. 381,994 I Y 12' claims. (ci. 9s`9) This invention relates to photographic illm and Kmore particularlyto photographic illm protected against halation.' A -Light-absorbingcoatings on the backs of photographic films are well known to the art of halation prevention. Generally, these antihalation coatings consist of a. carrier material and a lightabsorbing material such as a dye or pigment, and

are removable or non-removable according to the solubility characteristicsof the carrier material.

The coatings are applied, as a rule, to the rear.

side of a iilm support which may be a cellulose ester, a synthetic resin br other material.

lulose acetate suppolrt is suilic'iently good that itl it is not necessary to employ an adhesive `layer to `join the antihalation layer to the illm support. However, in the case of photographic filml supports consisting of mixed esters of` cellulose, such as substantially unhydrolyzed cellulose acetate propionate and cellulose acetate butyrate the adhesion of cellulose acetate dicarboxylic acid ester y antihalation layers is so poor that an adhesive layer must be used between the iilm support and the antihalation backing layer to prevent stripping of the backing layer` from the support.

The rprincipal object of the present invention emulsion, and on the opposite' side of the'supis to provide a cellulose mixed-ester film support I lulose mixed organic acid dicarboxylic acid esters ers according to our invention. y

Another object is to describe the method of applying, to rilm supports, cellulose mixed orwhich may'beused for antihalationbacking layganic acid dicarboxylic acid esters which are removable in photographic processing solutions.

Another object is to deszribe the method of applying to lrn supports,` cellulpse mixed organic acid dicarboxylic acid esters which are non-removable in photographic processing solutions.

These objects are accomplished in the present ter adhesively joins the invention by subbing layers which adhesively ,join antihalation layers of cellulose mixedl organic acid dicarboxylic acid esters to cellulose mixedl organic acid ester film supports.

In the accompanying drawing are illustrated the various methods we use for affecting adherence between antihalation layers and photographic film supports. f

Fig. 1 is an enlarged sectional view of a photographic antihalation iilm where a cellulose esfilm support.

Fig. 2 is an enlarged sectional view of a photographic antihalation film wherein a resinis used to `loin the antihalation layer to the support.

Fig. 3 is an enlarged sectional view of a photographic antihalation film wherein a mixture of a cellulose ester and a resin is used for joining the antihalation layer to the film support.

The method we use for accomplishing' the objects of our invention depends upon-the initial observation, above mentioned, that antihalation backing layers, such as cellulose acetate phthalate, adhere well to supports such as partially hydrolyzed cellulose acetate, however, do not adhere well to substantially unhydrolyzed cellulose mixed ester supports such as cellulose acetate propionate. Therefore, in the'manner of our invention, we provide cellulose mixed ester supports such as cellulose acetate propionate, with 'an port, with a layer of cellulose acetate or partially hydrolyzed cellulose mixed organic acid ester, over which layer cellulose acetate dicarboxylic acid esters may be coated with good adherence. The backing layers are usually coated before the emulsion layer is applied.v

On the other hand, when we wish to coat cel-'- lulose acetate butyrate iilm supports with an antihalation layer such as cellulose acetate phthalate, we iind that cellulose acetate phthalate will -not adhere well to either the uncoated support or to the support coated'with cellulose acetate. Therefore, before coating the antihalation layer we provide such supports with a vlayer of a partially hydrolyzed cellulose acetate or cel-4 lulose mixed organic acid ester. We may even first coat the support with a layer of well esteried cellulose ester such as cellulose acetate propionate, followed by a layer of cellulose acetate to which the antihalation layer will adhere satisfactorily.

In a similar manner, when adapting our subbing layers to cellulose acetate phthalate backing layers having a wide range or -phthalyl conantihalation layer tothe tent and which may be either removable or nonremovable in photographic processing solutions, we choose a cellulose ester subbing layer which will satisfactorily Join the particular backing layer to the particular cellulose mixed ester support.

In addition to the use of cellulose esters for the adhesive layers we may use synthetic resins or mixtures of synthetic resins and cellulose esters. Such resins are the commercially well known Glyptal and Santollte resins.

For the light absorbing component of the antlhalation backing layers we may use dyes or colloidal carbon. 'I'he use of cololidal carbon in y antihalation layers similar to those of the present invention has been disclosed in a prior lyzed cellulose acetate propionate, and a cellulose acetate phthalate layer I5 containing a dye or colloidal carbon.

In Fig. II is shown a sectional view of a film havingk a cellulose mixed organic acid ester support I0 provided, on one side, with an emulsion layer il and on the opposite side, with an antihalation layer I5 of cellulose acetate phthalate containing a dye or colloidal carbon, adhesively joined to the support by means of the resin subbing layer Il consisting of a resin, such as, a

- Glyptal or Santolite resin.

In Fig. III is shown a modification of our invention wherein a cellulose mixed organic acid ester film support I0 is provided on one side with an emulsion layer II, and on the opposite side with an antihalation layer I5 of a cellulose acetate phthalate adhesively joined to the support by means of layer I4 which consists of a mixture of a cellulose ester and a resin, such as a Glyptal or Santolite resin.

The following examples describe the method of coating antihalation backing layers in the manner of our invention.

Example I A cellulose acetate propionate film support, 16% propionyl and 29% acetyl, plasticized in a known manner and provided with a sensitive emulsion, was coated with a solution of cellulose acetate, containing about `38% acetyl, from a solvent mixture of the following composition:

Per cent Cellulose acetate 3.0 Acetone r10.0 Mfelil'iyl alcohol 27.0

Over this layer was applied a solution of cellulose acetate phthalate, approximately 2530% phthalyl and 22-24% acetyl, from a solvent mixture of the following composition:

- Per centv Cellulose acetate phthalate 13.0 Water 20.0 Methyl Cellosolve 20.0 Ethyl alcohol 47.0

The cellulose acetate phthalate backing was then colored with an ethyl alcohol solution of spirit nigrosine dye (Color Index No. 846) containing 3% Aerosol AY. Over the tinted layer may be applied a carbon tetrachloride solution of carnauba wax or a basic material such as triethanolamine, ammonia, dioctylamine, tributylamlne, diamylamine, etc. The antihalation layer is'removable in alkaline photographic processing solutions.

Example II Using the same film support and cellulose acetate undercoat as that described in Example I, the -aitihalation layer may consist of a disper- 'sion of carbon in cellulose acetate phthalate coated from a mixture of the following composition:

I Per cent Acetone 10.0 lMethyl Cellosolve 26.0 Ethyl alcohol 40.0 .Water s 16.0

Cellulose acetate phthalate and carbon mixture in'ratio 3 to l 8.0 Carnauba Wax may be coated over this layer.

Example III Cellulose acetate propionate and cellulose acetate butyrate supports coated, respectively, with cellulose acetate and cellulose acetate propionate as described in Examples I and III, were overcoated with a layer of cellulose acetate phthalate lcontaining 27% acetyl and 13% phthalyl, from a solvent mixture of 45% acetone and 55% methanol wherein the cellulose ester concentration was 3%. The backing layer was then tinted with a dye such as Acid Blue 3R using a 2.5% solution of the dye in a solvent mixture of 55% ethyl alcohol, 35% methyl Cellosolve, and 10% water. Over the tinted antihalation layer may be applied a thin layer of wax or lbasic material.

The above described antihalation layer is typical of the non-removable type previously referred to. When a photographic lm so provided, is subjected to the action of photographic processing solutions the backing layer swells, exposing the dye to reagents which bleach and remove it from the film. Antihalation layers of this typeare described in our application Nadeau and Slack Serial No. 381,695, filed March 4, 1941.

The above examples may be further amplilied by the use of various partially hydrolyzed cellulose acetate propionates, such as,one containing 15% propionyl and 23% acetyl, for an undercoating on cellulose acetate propionate and cellulose acetate butyrate film supports of the composition shown in Examples I and III.

These coatings may also be applied from solvent' mixture of acetone and methanol, and are followed by a layer of. cellulose acetate phthalate which is then tinted with a dye. f

'Example V A cellulose acetate propionate nlm support plasticized in a known manner was coated withV a mixture of a resin and cellulose acetate, *38% acetyl, using a coating A cellulose acetate phthalate layer ofthe composition described in Example Lwas coated over this layer Iand tinted with Nigrosine dye.

In addition to the above mentioned antihalation backing layers consisting of cellulose acetate phthalate we may use other` cellulose mixed organic acid dicarboxylic acid esters with equal success, such as cellulos'efpropionate phthalate, acetate succinate, acetate maleate, etc. 'I'he method we use is to determine the composition of a cellulose ester to which thesematerials will adhere and use this ester as the adhesive joining layer between the Vantihalation layer and the 4 film support. f

solution of the following '4. A photographic film free from halation4 which comprises a substantially unhydrolyzedY one side with a. light sensitive emulsion layer, and on the opposite side, with a layer of hydrolyzed cellulose acetate, and a layer containing cellulose acetate phthalate and a light-absorbing material.

5A photographic film free yfrom halation 'which comprises a substantially unhydrolyzed cellulose acetatepropionate support provided on one side with a light sensitive emulsion layer, and on the opposite side, with a layer of hydrolyzed cellulose acetate, and a layer containing cellulose acetate phthalate, per cent phthalyl and 23 per cent acetyl, and a light-absorbing material.

' 6. A photographic nlm free from halation v which comprises a` substantially unhydrolyzed The dicarboxylic acid acyl content of the backing layers is not critical, however, the higher this value is the more easily removable this layer will be. Where the dicarboxylic acid acyl content is lowthe antih'al-ation layer is swellable, but non-removable in photographic processing solutions, providing that the organic acid ester content of the mixed organic acid dicarboxylic acid ester is not too low.

While we mention the use of only cellulose organic acid esters as components of the layers which are used tojoin antihalation layers to a lm support-we may, however, use an inorganic acid ester of cellulose such as cellulose nitrate,

in which case we prefer to use colloidal carbon in the antihalation layer rather than a dye, since cellulose nitrate has a tendency to absorb dyes and hold them fast to removal by photographic processing solutions.

It is to b understood that the disclosure herein is by way of example and that we consider as included in our invention all modiilcations and equivalents falling within the scope oi the appended claims. i

What we claim is l. A photographic illm free fromV halation which comprises a substantially unhydrolyzed cellulose mixed organic acid ester support procellulose acetate propionate support provided on one side with a light sensitive emulsion layer, and

, cellulose acetate propion'ate support provided on on the opposite side, with a layer of hydrolyzed cellulose acetate, and a layer containing cellulose acetate phthalate and colloidal carbon.

i 7. A photographic illmv free from halationl which' comprises a substantially unhydrolyzed cellulose acetate butyrate support provided on one side with a light sensitive emulsion layer, and

on the opposite side, with a layer of hydrolyzed cellulose acetate propionate, and a layer containing cellulose acetate phthalate and a lightabsorbing material.

8. A vphotographic 111m free from halation which comprises a substantially unhydrolyzed cellulose acetate butyrate support provided on oneside with a light sensitive emulsion layer, and,

on the opposite side with a layer of hydrolyzed cellulose acetate propionate, and a layer containing cellulose acetate phthalate, 13 per cent phthalyl and 27 per cent acetyl, and a lightvided on one side with a light sensitive emulsion layer, and on the opposite side, with a layer comprising a hydrolyzed cellulose organic vacid ester, and a layer containing a cellulose mixed organic acid dicarboxylic acid ester and a light-absorbing material.

2. A photographic' film free from halation which comprises a substantially unhydrolyzed cellulose mixed organic acid ester support provided on one side with'a light sensitive emulsion layer, and on the opposite side, with a layer comprising a hydrolyzed cellulose organic acid ester,

and a layer containing cellulose acetate phthalate and a light-absorbing material.

3 A photographic film free from halation which comprises a substantiallyv unhyclrolyzed cellulose mixed organic acid ester support provided on one side with a light sensitive emulsion layer, and on the opposite side. with a layer comprising hydrolyzed cellulose acetate, and a layerl containing cellulose acetate phthalate and a light-absorbing material. l

absorbing material.

9. A photographic illm free `from halation which Vcomprises a substantially unhydrolyzed cellulose acetate butyrate support providedon one side with a light sensitive emulsion layer and, on

the opposite side, with a layer of hydrolyzed cellulose acetate propionate, and a layer containing cellulose acetate phthalate and a dye.

10. A photographic nlm free from halation which comprises a substantially unhydrolyzed cellulose acetate propionate support provided on one side .with a light sensitive emulsion layer, and on the opposite side, with a layer consisting of 1a mixture of hydrolyzed cellulose acetate and glyptal resin, and a layer containing cellulose acetate phthalate and a light-absorbing material.

l1. A photographic .llm free from halation which 4comprises a substantially unhydrolyzed cellulose acetate propionate support provided on one side with a light sensitive emulsion layer, and on the opposite side, with'a layer consisting of a mixture of hydrolyzed cellulose acetate and glyptal resin, and a layer containing cellulose acetate phthalate, 30 per cent phthalyly and 23 'per cent acetyl, and a light-absorbing material.

and on the opposite side, with a layer consisting of a mixture oi' hydrolyzed cellulose acetate and slyptal resinf and a layer containing cellulose acetate phthalate and colloidal carbon.

GALE F. NADEAU. ALFRED D. SLACK. 

